\documentclass[12pt]{article}

\title {State transition table}

\begin{document}
	\begin{center}
		{\large \textbf{\textsc{State transition table}}}\\\vspace{12mm}

		\begin{tabular}{ | l | l | l | l | l | l |}
			\hline
    			& Nuc & escapeChar & N Nuc & 4th N Nuc & endSeq				\\ \hline
			start & stateNuc & stateRareSeq & Error & Error & Exit			\\ \hline
			stateNuc & stateNuc & stateRareSeq & Error & Error & Exit 		\\ \hline
			stateRareSeq & stateNuc & stateRareSeq & stateReadingN & Error & Exit 	\\ \hline
			stateReadingN & Error & Error & stateReadingN & start & Exit		\\ \hline
		\end{tabular}
	\end{center}
\end{document}
